Levels and congener distributions of PCDDs, PCDFs and non-ortho PCBs in Belgian foodstuffs--assessment of dietary intake

Removal of dioxins and dioxin-like PCBs from fish oil by countercurrent supercritical CO2 extraction and activated carbon treatment

It has been known that fish oils are prone to contamination by polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs). In this study, the removal of contaminants from fish oil by countercurrent supercritical CO(2) extraction (CC-SCE) and activated carbon treatment was investigated. Fish oil was treated by CC-SCE at 70 degrees C and 30MPa and with a CO(2)/oil ratio of 72; this resulted in a 93% reduction in the sum of PCDDs, PCDFs and DL-PCBs concentration level by and 85% reduction in toxic equivalency (TEQ). CC-SCE uses 40% less CO(2) and yields 30% more refined oil than semi-batch-type processes. Subsequent treatment by activated carbon reduced the concentration level by 94% and TEQ by 93%. CC-SCE is effective for the removal of DL-PCBs, whereas activated carbon treatment is effective for the removal of PCDD/Fs. These results reveal that the combination of CC-SCE and activated carbon treatment is applicable to the removal of PCDD/Fs and DL-PCBs from fish oil.

Simultaneous quantitation of multiple classes of organohalogen compounds in fish oils with direct sample introduction comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry

We successfully optimized an analytical method using gel permeation chromatography followed by direct sample introduction comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry to quantify multiple groups of targeted persistent organic pollutants and halogenated natural products (HNPs) simultaneously in fish oil samples. This new method has a wider analytical scope than the traditional approach to use multiple methods to cover each class of compounds. Our analysis revealed that the relatively more volatile and lighter organic compounds, such as polychlorinated biphenyls (PCBs), organochlorine pesticides, and other smaller organohalogen compounds, were still present in two brands of "PCB-free" cod liver oils, albeit at much lower levels than in an untreated commercial sample. Moreover, the less volatile organic compounds, such as polybrominated diphenyl ethers and brominated HNPs, were detected at similar levels in all three cod liver oils. This suggests that the commercial molecular distillation treatment used for removal of organic/inorganic toxic contaminants is only effective for the lighter organic contaminants.

Modeling the exposure of children and adults via diet to chemicals in the environment with crop-specific models

Exposure to chemicals via diet is a major uptake pathway for many compounds but is often estimated in a rather generic way. We use a new model framework (NMF) with crop-specific models to predict the dietary intake by 4-5-year-old children and 14-75-year-old women of three environmental compounds from their background concentrations in soil and air. Calculated daily intakes of benzo(a)pyrene and 2,3,7,8-TCDD are in good agreement with measured results from diet studies. The major source of both compounds in human diet is deposition from air. Inhalation of air and ingestion of soil play a minor role. Children take up more than twice the amount than adults per kg bodyweight, due to higher consumption per kg bodyweight. Contrary, the methods for indirect human exposure suggested in the Technical Guidance Document (TGD) for chemical risk assessment in the EU lead to overprediction, due to unrealistic consumption data and a false root model.

Human exposure to PCDDs, PCDFs and dioxin-like PCBs associated with seafood consumption in Korea from 2005 to 2007

Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DLPCBs) were measured in 26 seafoods commonly consumed by the Korean population. The total toxic equivalent (TEQ) concentrations in seafood samples ranged from 0.01 to 6.76 pg TEQ/g wet wt, which were comparable with those found in other countries. The predominant congeners found in seafood samples were 2, 3, 4, 7, 8-PeCDF and 2, 3, 7, 8-TCDF for PCDD/Fs and PCB 118 for DLPCBs. Dietary intakes of PCDD/Fs and DLPCBs from seafood consumption were estimated for various age groups and gender in Korea. The dietary intake of PCDD/Fs and DLPCBs from seafood consumption for the general population was estimated to be 1.23 pg TEQ/kg bw/day, values that are in the range of those reported for other countries. Mackerel, tuna and hairtail contributed to the highest TEQ intakes, which collectively accounted for 66% of the total intake. Among the eight age groups investigated, 3-6 year old children had the highest TEQ exposure, followed by 50-64 years, 30-39 years and <2 years. Considering contributions of seafood consumption to the total dietary intake studies, the dietary TEQ intakes to the general population appear to be below the threshold values by international organizations. The present study may be useful for risk management for dioxins and dioxin-like contaminants in Korean seafood.

Methods for determining pesticides and polychlorinated biphenyls in food samples--problems and challenges

Determination of residual amounts of pesticides and polychlorinated biphenyls (PCBs) in food samples requires the use of specific techniques regarding sample preparation as well as instrumental analysis which should be characterized by a very low detection limit. A problem associated with the use of pesticides and PCBs is the need for controlling their residues in the environment, particularly in food, as these chemicals show a propensity to accumulate. The analysis of food samples for the presence of pesticides and PCBs brings on many difficulties because of the specificity of sample preparation consisting of multistep purification procedures of samples that contain trace amounts of an analyte. Concentration determinations of pollutants that easily dissolve in complex matrices, particularly in the presence of a large apportionment of interfering substances, pose a big challenge. Therefore, the basic step in food analysis for the presence of pesticides and PCBs is sample preparation which mainly consists of analyte enrichment and the removal of interfering substances. But all steps of the analytical procedure that include sample collection and preparation, extraction of analytes from matrix, extract purification, and final determination, are very significant; their precision and correct application have a decisive effect on the final result.

Dietary intake of PCDDs/PCDFs and coplanar PCBs among the Japanese population estimated by duplicate portion analysis: a low proportion of adults exceed the tolerable daily intake

Dietary intake of dioxins was estimated by duplicate portion analysis of consecutive 3-day food samples among 86 men and 288 women (aged 17-72 years), who were living in 75 different areas of 25 prefectures in Japan. The mean (median) intake of PCDDs+PCDFs, coplanar PCBs (co-PCBs), and total dioxins, expressed on the basis of toxicity equivalents (TEQ), was 0.46 (0.34), 0.59 (0.39), and 1.06 (0.79)pg/kg body weight/day, respectively. Dietary intake was highest in fishing areas, followed by farming and urban areas. In multiple regression analysis, TEQs of PCDDs+PCDFs, co-PCBs, and total dioxins were positively associated with age and intake amount of fish and shellfish, and milk and dairy products, and negatively associated with survey year. There were significant positive correlations between dietary intake and blood levels for TEQs of PCDDs+PCDFs, co-PCBs, and total dioxins (Pearson r=0.35-0.36). The proportion of those whose dietary intake exceeded the tolerable daily intake (TDI), set by the World Health Organization (4pg TEQ/kg/day) and European Union (2pg TEQ/kg/day), was estimated at 2.1% and 10.4%, respectively. However, these proportions were considered to be overestimated because of the effect of day-to-day within-person variation. Therefore, the ratio of within- and between-person variance was estimated by applying random effects one-way analysis of variance to repeated measurements for another group of 35 persons. When the effect of within-person variation of dietary intake was accounted for, the proportion of subjects whose long-term intake exceeded the TDI of WHO and EU decreased to 0.06% and 2.9%, respectively.

Exposure to dioxin-like pollutants via different food commodities in Swedish children and young adults

The dietary intake of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) in terms of toxic equivalents (TEQs) was investigated in Swedish children and young adults. Exposure was estimated from concentration data of six groups of individual food commodities (meat, fish, dairy products, egg, edible fats and other foodstuff) combined with food intake data from a 7-day record book obtained from 670 individuals aged 1-24 years. The results showed that Swedish boys and girls, up to the age of ten, had a median TEQ intake that exceeded the tolerable daily intake (TDI) of 2 pg TEQ/kg body weight. Children exceeding the TDI varied from almost all individuals among the youngest children to about 20% among young men and women. Dairy and fish products were the main sources of exposure for the average child, accounting for 59% of the total TEQ intake. The individuals most highly exposed were, on the other hand, characterized by a high consumption of fish. Since children constitute a vulnerable group, results obtained from the present study show that it is essential to perform age specific dietary intake assessments of pollutants and more carefully consider sensitive and/or highly exposed groups in the population in the risk management processes.

Effects on growth and biochemical responses in juvenile gilthead seabream 'Sparus aurata' after long-term dietary exposure to low levels of dioxins

The farmed fish gilthead seabream (Sparus aurata) were fed with a dry feed spiked with a low level (23 ng WHO-TEQ/kg of feed) polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) mixture in order to assess bioaccumulation of these contaminants in the muscle and liver tissues after long-term exposure (approximately 390 days). Furthermore, effects on fish growth, feeding and on the response of some biochemical markers (induction of the CYP1A dependent EROD activity, the conjugating enzyme GST, the antioxidant enzymes CAT, t-GPX and DTD, lipid peroxidation and the AhR gene expression) were also evaluated. After feeding with the spiked dry feed for 3 months the PCDD/F concentrations in the exposed fish were 5.50 pg WHO-TEQ/g fresh weight (f.w.) in flesh and 8.45 pg WHO-TEQ/g f.w in liver tissue, which are approximately 24-fold and 14-fold higher than background levels, respectively. However, a progressive increase in PCDD/F levels was not found during the rest of the exposure period. Differences in fish growth were not observed between dioxin-exposed and non-exposed animals and, in addition, no mortalities were recorded attributable to the dioxin intake. Significant increases in the EROD activity, as well as in AhR gene expression were observed in liver after approximately 300 days of exposure. However, no effect on the antioxidant enzymes CAT and t-GPX was found.

Comparison of levels of polychlorinated biphenyls in edible oils and oil-based products--possible link to environmental factors

Food consumption has been widely reported to be the main source of human exposure to PCBs. A total of 47 samples of food products on sale in supermarkets in the United Kingdom were thus analyzed for PCBs to determine residual levels in oil and oil-based products. The objective was to compare the measured levels of total PCBs (Sigma PCBs) in food products to those reported in various environmental compartments. Combined extraction and online clean up was achieved using Accelerated Solvent Extraction (ASE) to recover target analytes for analysis by GC-MSD (gas chromatography mass spectrometry). Sigma PCBs (ng/g) in each product were in the ranges of 4.73-44.38 edible oil; 1.40-6.18 mayonnaise; 1.21-6.25 salad cream; 1.28-5.64 seafood sauce, and 0.97-15.08 exotic dressing. The level of human exposure to PCBs in all products was < 1 microg/kg body weight/day when considering a 70 kg male or 57 kg female, possibly reflecting the reported decline of PCBs in the environment.

Relationship of PCDD/Fs congener profiles between beef and raw milk in South Korea

The relationship between profiles of residual PCDD/Fs in beef and raw milk was examined by measuring concentrations and detected frequencies. Unrelated samples of beef and raw milk were collected from nine regions in South Korea. Congener-specific profiles of PCDD/Fs in beef and raw milk were very similar. PCDFs, particularly 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, 1,2,3,6,7,8-HxCDF, and 2,3,4,6,7,8-HxCDF, were dominant congeners in both beef and raw milk suggesting that sources of contamination may not significantly differ nationwide. The profiles of PCDD/Fs in domestic beef and raw milk in this study were closer to the profiles of emission from metal industries although Korea imports over 75% of feedingstuffs. The ratios of PCDF/PCDD in TEQ concentration were more than 5 and 15 in beef and raw milk, respectively. The mean concentrations of PCDD/Fs in 60 samples of beef and 60 samples of raw milk were 0.80 pg WHO-TEQ/g fat and 0.65 pg WHO-TEQ/g fat, respectively. The residual profiles of PCDD/Fs in raw milk resembled that in beef although the congener profiles might change throughout the food chain. This indicated that monitoring of dioxins in milk could provide information for contamination of milk itself or other associated food.

Dietary exposure to dioxin-like compounds in three age groups: results from the Flemish environment and health study

Lipophilic contaminants are present in the environment and bioaccumulate in the food chain. Therefore, their intake via animal fat of various sources was assessed for three age groups of the Flemish population, participating in a large biomonitoring program of the Flemish government. In total, 1636 adolescents (14-15 years), 1186 mothers (18-44 years), and 1586 adults (50-65 years) participated in the study and completed a semi quantitative food frequency questionnaire. Individual consumption data were combined, via a so-called simple distribution approach, with recent data on polychlorinated dibenzo-p-dioxins/furans and dioxin-like polychlorinated biphenyls, measured via the chemical-activated luciferase gene expression (CALUX) bio-assay in food items available on the Flemish market. The median (95th percentile) estimated intakes of dioxin-like contaminants were 2.24 (4.61), 2.09 (4.26), and 1.74 (3.53) pg CALUX-TEQ kg(-1) bw d(-1) for, respectively adolescents, mothers and adults. These data are in the same range as those found in other European studies. The CALUX-TEQ results of respectively 59.8%, 53.7% and 36.2% of the adolescent, mother and adult population exceed the tolerable weekly intake (TWI) of 14 pg WHO-TEQ kg(-1) bw w(-1), as derived by the Scientific Committee on Food [Scientific Committee on Food, 2001. Opinion of the Scientific Committee on Food on the Risk Assessment of Dioxins and Dioxin-like PCBs in Food, CS/CNTM/DIOXIN/20 final Brussels, Belgium]. The main contributors of dioxin-like substances are fish and seafood (25-43% of the total intake), added fats (22-25% of the total intake) and dairy products (17-20% of the total intake).

High variation of PCDDs, PCDFs, and dioxin-like PCBs ratio in cooked food from the first total diet survey in Taiwan

This study determined the levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in 240 individual food samples, belonging to 37 different foodstuffs in first total diet study (TDS) in Taiwan. The foods were collected from markets located in eight cities or counties around Taiwan. The food was cooked in a laboratory according to recipes typically used in Taiwan. In this study, PCDD/Fs were lower than the limits proposed by the European Union (EU) regulation for commercialized food, except for a notable PCDD/Fs level in ducks (3.660 pg WHO-TEQ/g, fat) obtained from central Taiwan. We hypothesize the duck meat might be probably polluted via emission of a fly ash recycling plant located near the duck farms. In addition to fish, most foods had high PCDD/Fs to dl-PCBs ratio. Needle fish and sea perch had relatively lower PCDD/Fs and dl-PCBs levels compared with those in other fish. Data from this study can be utilized for further consideration about dietary intake.

Ion-trap tandem mass spectrometry for the analysis of polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in food

This paper reports on the applicability of gas chromatography coupled to ion-trap tandem mass spectrometry (GC/ITMS/MS) for the analysis of polychlorinated dibenzo- p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in food. MS/MS parameters were selected to achieve the high sensitivity and selectivity required for food analysis. Good precision (RSD=5-18% for PCDD/Fs and 6-14% for dl-PCBs) and low limits of detection for PCDD/Fs (0.1-0.93 pg/g of fat) and dl-PCBs (0.1-0.89 pg/g of fat) were obtained. A comparative study of the congener-specific determination using both GC/ITMS/MS and GC-high resolution mass spectrometry (GC/HRMS) was performed by analyzing several matrices such as milk, fish oil, chicken, pork, fish, eggs, and a chicken compound feed, at low pg/g levels. The results using GC/ITMS/MS were in good agreement with those obtained by GC/HRMS. Consequently, GC/ITMS/MS is proposed for the analysis of PCDD/Fs and dl-PCBs in food and feed samples.

Development and application of a simplified clean-up procedure for the determination of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in horse fat by gas chromatography-tandem mass spectrometry (GC-MS/MS)

A simplified clean-up procedure was developed in combination with gas chromatography-tandem mass spectrometry (GC-MS/MS) for the determination of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in adipose tissue. Clean-up was performed by the successive application of a Mega Bond Elut silica column and a Bond Elut PCB column. Validation of the method was conducted according to European Union Commission Decision 2002/657/EC. In order to evaluate the applicability of the method, 44 horse fat samples were analysed. The total PCB concentration (sum of PCBs 28, 52, 101, 118, 138, 153 and 180) ranged from 5.35 to 140 ng g(-1) lipid weight. The total PBDE concentration (sum of BDEs 28, 47, 99, 100, 153, 154 and 183) ranged from below the decision limit to 6.34 ng g(-1) lipid weight.

Polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in fish from the Netherlands: concentrations, profiles and comparison with DR CALUX® bioassay results

Fish from Dutch markets were analysed for concentrations of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) and compared with the new European maximum residue levels (MRLs), set in 2006. In a first study on 11 different fish and shellfish from various locations, concentrations of PCDD/Fs were nearly all below the MRL for PCDD/Fs [4 pg toxic equivalents (TEQ) per gram wet weight (ww)] and nearly all below 8 pg total TEQ/g ww, the new MRL for the sum of PCDD/Fs and DL-PCBs. Some samples exceeded the total TEQ MRL, such as anchovy, tuna and sea bass. Furthermore, 20 (out of 39) wild eel samples exceeded the specific MRL for eel (12 pg total TEQ/g ww), as the study revealed PCDD/F TEQ levels of 0.2-7.9 pg TEQ/g ww and total TEQ values of 0.9 to 52 pg/g ww. TEQ levels in farmed and imported eel were lower and complied with the MRLs. Smoking eel, a popular tradition in the Netherlands, only had marginal effects on PCDD/F and DL-PCB concentrations. Owing to volatilization, concentrations of lower-chlorinated PCBs were reduced to below the limit of quantification after smoking. DL-PCBs contributed 61-97% to the total TEQ in all eel samples. This also holds for other fish and shellfish (except shrimps): DL-PCB contributed (on average) from 53 (herring) to 83% (tuna) to the total TEQ. Principal-component analysis revealed distinctive congener profiles for PCDD/Fs and non-ortho PCBs for mussels, pikeperch, herring and various Mediterranean fish. The application of new TCDD toxic equivalency factors (TEFs) set by the World Health Organization in 2006 (to replace the 1997 TEFs) resulted in lower TEQ values, mainly owing to a decreased mono-ortho PCB contribution. This decrease is most pronounced for eel, owing to the relative high mono-ortho PCB concentrations in eel. Consequently, a larger number of samples would comply with the MRLs when the new TEFs are applied. The DR CALUX(R) assay may be used for screening total TEQ levels in eel, in combination with gas chromatography-high resolution mass spectrometry confirmation of suspected samples. An almost 1:1 correlation was found when the 1997 TEFs were applied, but, surprisingly, a 1.4-fold overestimation occurred with application of the 2006 TEFs.

Analysis of polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls in vegetable oil samples by gas chromatography–ion trap tandem mass spectrometry

Gas chromatography coupled to ion trap tandem mass spectrometry (CG-MS-MS) has been evaluated for the analysis of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in vegetable oil samples containing different concentration levels (0.2-6 pg WHO-TEQ g(-1) for both PCDD/Fs and dl-PCBs) of the 29 toxic congeners of PCDD/F and dioxin-like PCBs. The effect of potential interfering compounds such as polychlorinated naphthalenes (PCNs), polychlorinated biphenyls (PCBs) and polychlorinated diphenylethers (PCDEs) on the quantification of mono-ortho PCBs has been investigated. In addition, the influence of the clean-up procedure on the final determination by CG-MS-MS was studied, showing that the quality of the results depends to a great extent on this analytical step. Quality parameters have been established and good precisions (CV: 3-19%) and low limits of detection for PCDD/Fs (0.04-0.20 pg g(-1) oil) and dl-PCBs (0.08-0.64 pg g(-1) oil) were obtained. The method was validated by a comparison of the CG-MS-MS results with those obtained by GC-HRMS.

Organochlorinated contaminants in decapod crustaceans from the coasts of Brittany and Normandy (France)

The contamination and distribution of organochlorinated compounds were considered in three crustacean species (edible crab, Cancer pagurus; spider crab, Maja brachydactyla; velvet swimming crab, Necora puber) from five sites along the coasts of Brittany and Normandy (Western and North-Western France). PCBs (16 single congeners), pp'-DDE and HCB were measured in hepatopancreas, gonads and muscle: in all, 175 samples were analysed. The spider crab was the only species found in the five sampling sites, thus enabling comparison between areas. Specimens from Antifer were much more contaminated (summation operator 16 PCBs in hepatopancreas=2000-4000 ng g(-1) dry weight) than those from other sites (50-1000 ng g(-1) d.w.). Among all the three species, the spider crab appeared more contaminated by PCBs than the edible crab, by a factor 2-3, probably in relation with specific differences in their life cycle. There was no difference due to the gender of the species. Within the different analysed tissues, contamination levels increased from muscle to gonads and hepatopancreas in relation with the fat content. A very similar PCB composition was observed in all samples, PCB fingerprints being characterised by the relative importance of the more persistent PCB congeners: CB153, 138, 180, 187, and 118. Finally, these results were compared to recent food regulations first of maximum marker PCB intake and secondly of maximum dioxin-like PCB intake. By considering the muscle, all samples were far below the regulatory limits; for hepatopancreas and gonads, however, some samples were unfit for human consumption.

A total diet study to estimate PCDD/Fs and dioxin-like PCBs intake from food in Taiwan

Concentrations of 17 dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were measured in total diet study samples of 14 food groups of animal origin from 11 locations in Taiwan, collected in 2003. Pork meat possessed the lowest background concentration level of 0.058 pg WHO-TEQ(PCDD/Fs+dl-PCBs)/g fresh weight. The dl-PCBs contribution were 31%, 59%, 36%, 46%, and 13% for meat and meat products, muscle meat of fish, milk and dairy products, fat and oil, and egg, respectively. The estimated monthly intake (EMI) was 44.7 and 39.5 pg WHO-TEQ(PCDD/Fs+dl-PCBs)/kg b.w./month for a male and female adult weighing 64.8 kg and 56.3 kg, respectively. Muscle meat of fish contributes 46% to the mean EMI. Factors affecting the EMI, in order of increasing importance are analytical method uncertainty, sample compositional difference, and food consumption data. In addition to the continuous efforts to identify and reduce the source of PCDD/Fs and dl-PCBs releases into the environment and the food-chain, the practice of a healthy dietary habit, i.e., eating foods of lower TEQ levels, was suggested to effectively reduce human exposure to PCDD/Fs and dl-PCBs.

PCDD/F levels in plasma of a belgian population before and after the 1999 belgian PCB/DIOXIN incident

We evaluated the impact of the 1999 Belgian dioxin incident on the blood plasma polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) levels among 232 Belgian blood donors (74% men, mean age 47 years). The Red Cross made plasma samples from before the incident of these donors available. A second plasma sample was collected during the second half of 2000. The sum of the 17 PCDD/F congeners was significantly lower in 2000 compared to 1998 (417 pg/g fat versus 445 pg/g fat, respectively). This could be completely attributed to the significant decrease of OctaCDD (301 pg/g fat in 2000 versus 277 pg/g fat in 1998). Moreover a slight but significant decrease was observed for 2,3,7,8-TetraCDF and for 1,2,3,4,6,7,8-HeptaCDF. 1,2,3,7,8-PentaCDF and 2,3,4,7,8-PentaCDF however showed a slight but significant increase (respective levels in 1998 were 0.004 and 14.5 pg/g fat compared to 0.006 and 17.9 pg/g fat in 2000). Given their significantly higher presence in incident related food samples this increase can be attributed to the food contamination episode. However, the total toxicity remained unchanged (22.9 in 1998 versus 23.1 pg WHO-TEQ/g fat, p>0.05). Moreover the observed congener profiles and the total PCDD/F levels were similar to those of other European non-occupationally exposed populations. In conclusion, the 1999 PCB/dioxin incident was traceable in the plasma profiles (rise of the two specific PCDF congeners), but comparison of the results for both years indicates that the changes were too small to cause an adverse public health effect.

Dietary intake of polychlorinated dioxins, furans and dioxin-like polychlorinated biphenyls from foods of animal origin in China

Four food groups of animal origin from the Chinese Total Diet Study (TDS) in 2000 were analysed for 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (PCBs). The samples were from four regions, covering 12 provinces of China. PCDD/Fs, expressed as WHO toxic equivalents (TEQ), ranged from 0.02 to 0.28 pg TEQ g-1 and dioxin-like PCBs ranged from 0.01 to 0.24 pg TEQ g-1 (wet weight, ND = LOD), in all samples. Using food consumption data from a 3-day household dietary survey, daily dietary intake of dioxin-like compounds from foods of animal origin in China was estimated. Daily intake among regions ranged 0.09-0.59 pg TEQ kg-1 body eight day-1.

Environmental and host-associated risk factors in endometriosis and deep endometriotic nodules: a matched case-control study

Peritoneal endometriosis (PE) and deep endometriotic nodules (DEN) are gynecological diseases recently shown to be associated with elevated serum concentrations of organochlorines. The objective of the present study was to compare risk factors associated with both forms of the disease, with a particular attention to potential sources of organochlorine exposure. This matched case-control study with prospective recruitment included 88 triads (PE-DEN-control). All women were face-to-face interviewed with a standardized questionnaire, and serum dioxin and polychlorinated biphenyl measurements were available for 58 of them. Alcohol consumption (odds ratio (OR): 5.82 [confidence interval at 95% (95%CI) 1.20-28.3]) in DEN and low physical activity at work for DEN (OR: 4.58 [95%CI 1.80-11.62]) and PE (OR: 5.61 [95%CI 1.90-16.60]) were traced as significant risk factors. Organochlorine-related factors (use of tampons, occupational or environmental exposure) were not related to the disease. The current consumption of foodstuffs that were more likely to contribute to organochlorine body burden did not differ among the groups. Only some of these fatty foodstuffs (marine fish, pig meat) were traced by multiple regression analysis as significant determinants of organochlorine body burden, explaining only a small fraction (20%) of the interindividual variation of organochlorine body burden. We conclude that PE and DEN share similar patterns of risk or protective factors.

Chemical contamination of free-range eggs from Belgium

The elements manganese, cobalt, nickel, copper, zinc, arsenic, selenium, molybdenum, cadmium, antimony, thallium, lead and mercury, and selected persistent organochlorine compounds (dioxins, marker and dioxin-like polychlorinated biphenyls, dichlorodiphenyltricholroethane (DDT) and metabolites as well as other chlorinated pesticides) were analysed in Belgian free-range eggs obtained from hens of private owners and of commercial farms. It was found that eggs from private owners were more contaminated than eggs from commercial farms. The ratios of levels in eggs from private owners to the levels in eggs from commercial farms ranged from 2 to 8 for the toxic contaminants lead, mercury, thallium, dioxins, polychlorinated biphenyls and the group of DDT. DDT contamination was marked by the substantial presence of p,p'-DDT in eggs from private owners in addition to dichlorodiphenyldichloroethylene (p,p-DDE) and dichlorodiphenyl-dichloroethane (p,p'-DDD). It is postulated that environmental pollution is at the origin of the higher contamination of eggs from private owners. Extensive consumption of eggs from private owners is likely to result in toxic equivalent quantity intake levels exceeding the tolerable weekly intake.

Body burden of dioxins and dioxin-like polychlorinated biphenyls in pregnant women residing in a contaminated area

A large pentachlorophenol (PCP)-manufacturing plant located in southwestern Taiwan operated between 1965 and 1982. The present study was conducted to ascertain whether an increased body burden of dioxins existed in pregnant women living in an area of Tainan city contaminated by chemicals from this plant. Twenty-eight pregnant subjects, 21-39 years of age and residing in the study area between March and December of 2004 with a mean dwelling time of 6.07+/-6.11 years, were recruited. Concentrations of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (PCBs) in serum of recruited residents were determined. Pregnant women residing in the study area >3 years had significantly higher PCDD (7.48 versus 5.13 pg-toxic equivalents [TEQ]/g-lipid) and dioxin-like PCB (6.70 versus 3.74 pg-TEQ/g-lipid) values as compared to those residing < or = 3 years. Furthermore, dioxin concentrations increased with increasing dwelling time. Statistical analyses performed according to demographic characteristics and socioeconomic and dietary habits revealed that total TEQ values were significantly associated with fish consumption and smoking status. Dioxin congeners with greater degrees of chlorine substitution (e.g., HpCDD/F and OCDD/F) partitioned to greater degrees in the subjects of this study as compared to subjects in the general Taiwanese population. The findings of this study strongly implicate the activity of the PCP manufacturing plant in the observed increase in dioxin body burden. Investigation of the health consequences of this increased body burden is recommended.

Dietary intake of dioxins and dioxin-like PCBs, due to the consumption of dairy products, fish/seafood and meat from Ismailia city, Egypt

Although dietary intake studies have been carried out extensively in most developed countries, to evaluate the health risks of PCDD/Fs and DL-PCBs, no data of this kind exists for Egypt. In this study, concentrations of PCDD/Fs and DL-PCBs were measured using HRGC/HRMS in the most contributing foodstuffs (dairy products, fish/seafood, and meat) randomly collected from Ismailia city, Egypt. The dietary intake of PCDD/Fs and DL-PCBs were subsequently determined, and compared with the most recent studies. To provide a primary estimation of the whole TEQ intake in Egypt if all the main food categories included, an estimation of the dietary intake (based on EU data) for some important and non-measured groups (cereals, vegetables/fruits, eggs and milk) was carried out. The calculated dietary intake based on the WHO assumption of 60 kg bw ranged from 3.69 to 4.0 pg WHO-TEQ/kg bw/day for PCDD/Fs and from, 6.04 to 6.68 pg WHO-TEQ/kg bw/day, if DL-PCBs were included. PCBs intake contributed about 40% of the total TEQ intake. Dairy products (mainly cheese) were the main contributor to the intake of PCDD/Fs (89%), while fish/seafood and meat have more or less the same percent share (5.4%). The dairy products contamination was the reason for our elevated dietary intake, as the content of PCDD/Fs and DL-PCBs is several times higher than in all the developed countries. The total intake (PCDD/Fs+DL-PCBs) due to consumption of dairy products, fish/seafood and meat, is close to that reported in EU countries at the beginning of 1980s, but much higher than all those mentioned in all the recent reports, and higher than the maximum WHO TDI of 4 pg TEQ/kg bw/day. A recalculation of the dietary intake to include not only our measured data but also the data for the non-measured groups, yielded a total intake in the range of 4.06-6.38 pg TEQ/kg bw/day for PCDD/Fs and a range of 6.59-9.98 pg TEQ/kg bw/day for total including PCBs. Results show that cereals and vegetables/fruits contribute significantly to PCDD/Fs TEQ intake in Egypt and play a more important role than fish/seafood and meat. This is the case even though the intake for cereals and vegetables/fruits based on EU data.

Current dietary exposure to polychlorodibenzo-p-dioxins, polychlorodibenzofurans, and dioxin-like polychlorobiphenyls in Italy

This study deals with an assessment of dietary exposure to polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), and dioxin-like polychlorobiphenyls (DL-PCBs) for the Italian general population, obtained by combining data from a national food consumption survey with contamination concentrations of European foodstuffs available on the market. The distribution of PCDD, PCDF, and DL-PCB dietary intake(s) in the Italian population was investigated to assess to what extent the variability in dietary habits may cause higher exposures to the previously mentioned contaminants. Results indicate that the main contributions to total PCDD, PCDF, and DL-PCB intake are due to fish and fish products (44%) and to milk and dairy products (27%). The mean PCDD, PCDF, and DL-PCB intake (total toxic equivalents) via food was estimated 5.34, 3.37, and 2.28 pg World Health Organization (WHO)-TE/kg of body weight (kg-bw) per day for the three age groups 0-6 (breastfeeding excluded), 7-12, and 13-94 years old, respectively. The highest exposures due to variation in dietary habits are in general within a factor of 2-3. From the mean exposure estimated for the general population (adults), it can be inferred that a consistent part of it would exceed the tolerable daily intake of 2 pg WHO-TE/kg-bw adopted by the Scientific Committee on Food of the European Commission in 2001.

Risk factors affecting blood PCDDs and PCDFs in residents living near an industrial incinerator in Korea

The contamination sources of polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), such as industrial incinerators, can potentially change the blood levels and isomer patterns of PCDD/DFs in residents living near the incinerators. In this study, we estimated whether the blood levels and isomer patterns of PCDD/DFs in residents living near an incinerator were affected by its presence and investigated factors that characterize the risk of high exposure to PCDD/DFs in the area. We estimated the blood levels and homologue patterns of PCDD/DFs in a group of 40 residents living within 5 km of an industrial incinerator and in a group of 20 residents living 20 km away from an incinerator. We cannot assert that the operation of incinerator facilities was only cause of increased PCDD/DFs in these residents; however, the operation of incinerator facilities in agricultural areas increased PCDD/DF exposure to individuals. The group living next to the industrial incinerator especially represented the typical isomer pattern in which the proportions of OCDDs were lower and those of PCDFs higher than those in the other groups. The high-risk population with increased blood levels of PCDD/DFs included those who had lived longer in the contaminated area as well as those who frequently ate contaminated foods.

Organochlorine compounds (PCBs, PCDDs and PCDFs) in seafish and seafood from the Spanish Atlantic Southwest Coast

Concentrations and congener specific profiles of PCDD/Fs and PCBs were determined in edible fish and seafood species from the Coast of Huelva, in the Spanish southwest Atlantic coast. Five fish species, namely wegde sole (Dicologoglossa cuneata), common sole (Solea vulgaris), white seabream (Diplodus sargus), sardine (Sardina pilchardus), angler fish (Lophius piscatorius), two shellfish species (Donax trunculus and Chamelea gallina), common cuttlefish (Sepia officinalis) and prawns (Parapenaeus longirostris), frequently found and consumed in the area were analysed. Concentrations ranged from 861 to 23787pg/g wet weight for total PCBs, while 2,3,7,8-PCDD/Fs showed concentrations ranging from 0.2 to 1.18pg/g wet weight. WHO-TEQ concentrations ranged from 0.038 to 0.186pg WHO-TEQ(PCDD/Fs)/g wet weight, values well below the maximum concentrations established by the EU. When non- and mono-ortho PCBs were included the values increased to a maximum of 0.99pg WHO-TEQ(PCDD/Fs+PCBs)/g wet weight. The PCB and PCDD/F accumulation pattern found in the samples analysed showed a distribution typically reported for marine samples, and no remarkable differences were found between species. The PCBs were the ones contributing with the highest percentage to the total TEQ content in most species studied. Concerning the seafood, specially prawns and shellfish, the opposite was observed and PCDD/Fs were found to contribute with a higher percentage than PCBs. The congener specific contribution to the TEQ showed PCB 126 followed by 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF as the most abundant ones.

Contamination of the alluvial plain, feeding-stuffs and foodstuffs with polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DL-PCBs) and mercury from the River Elbe in the light of the flood event in August 2002

Meadow soils, feeding-stuffs and foodstuffs from the alluvial plain of the river Elbe were analyzed in respect of PCDD/Fs, DL-PCBs and mercury with a view to assessing the consequences of the extreme flood of August 2002. The PCDD/F concentrations in the soils range from 3 to 2100 ng WHO-TEQ/kg dm, and for the DL-PCBs the range was 0.32 to 28 ng WHO-TEQ/kg dm. On the basis of established threshold values >40% of the areas are only fit for restricted usage. Mercury concentrations range from 0.11 to 17 mg/kg dm, whereby the action value of 2 mg/kg dm is exceeded in about 50% of the soil samples. A cumulative memory effect from past floods rather than a recent contamination from August 2002 is documented. Soils taken from behind broken dykes showed significantly lower concentrations. Grass, hay and grass silage originating from pasture land in Lower Saxony were taken before and immediately after the flooding. PCDD/Fs range from 0.29 to 16 ng WHO-TEQ/kg, the maximum permitted value of 0.75 ng WHO-TEQ/kg was exceeded in about 50% of the samples. Muscle-tissue from cattle, sheep, lamb and a roe deer as well as untreated milk from individual cows returned values ranging from 0.76 to 5.9 pg WHO-PCDD/F-TEQ/g fat, and 10% of the samples returned values higher than the permitted maximum of 3 pg WHO-PCDD/F-TEQ/g fat. The action value of 2 pg WHO-PCDD/F-TEQ/g fat was exceeded in 33% of the samples. No direct connection between these results and the effects of the flood could be established. A major input path for PCDD/Fs is the tributary Mulde, which discharges contaminated sediments from its catchment area into the Elbe.

Toxicokinetic study of dioxins and furans in laying chickens

Since foodstuffs from animal origin and particularly poultry products have been pointed out several times as reservoir of dioxins and related compounds, notably in Belgium few years ago, food chain safety issues appeared. Although food chain contamination incidents occurred many times through contaminated feedstuffs consumption in commercial chicken farms, very few studies have been carried out on transfer of dioxins and related compounds from commercial feed to hens. The present work continues a preliminary study on dioxin transfer in laying chickens carried out in our lab and available on-line on November 2004 in Environment International. In this work, absorption of dioxins were not preferential for 2,3,7,8-substituted congeners, increase with increasing number of chlorines, and was not linearly dependent of the octanol/water partition. Only 2,3,7,8-congeners were found in all organs studied, and these latter showed the same congener profile and similar lipid-normalized concentration, except for the liver. Abdominal fat and liver seemed to be the major storage sites and the liver preferentially retained highly chlorinated congeners. Unfortunately in this previous trial, laying process stopped very early for unknown reason leading to a considerable lost of information. In the present toxicokinetic study, more complete gastrointestinal absorption, excretion in eggs and bioaccumulation of dioxins in different tissues were investigated in chickens fed for 14 weeks with a 9 ng TEQ/kg contaminated feed. Stable levels were reached after 7 weeks in excreta and 9 weeks in eggs. During the whole trial, gastrointestinal absorption ranged between 41% and 91% depending on the congener. At steady state conditions, excretion of 1,2,3,4,6,7,8-HpCDD, OCDD, 1,2,3,4,6,7,8-HpCDF and OCDF exceeded 100% demonstrating excretion from tissues of these congeners which were also the most abundant in feed. 1,2,3,7,8-PeCDD, 1,2,3,7,8-PeCDF, 2,3,4,7,8-PeCDF, 1,2,3,6,7,8-HxCDF, 1,2,3,7,8,9-HxCDF and 2,3,4,6,7,8-HxCDF seemed to be metabolized more efficiently. Lipid adjusted concentrations and pattern were unexpectedly similar in the abdominal fat and the liver. On the contrary, eggs and breast muscles showed different pattern with higher level for high chlorinated congeners. When extrapolating our results, we found that a feed containing 0.750 ng TEQ/kg of dioxins (European norm for feedstuff) would cause a level lower than the maximum threshold level of 3 pg TEQ/g fat for chicken eggs fixed by European Communities. Nevertheless, a concentration lower than 0.6 ng TEQ/kg in feed would be needed to produce breast muscles less contaminated than 2 pg TEQ/g fat authorized in European.

Fish intake and serum levels of organochlorines among Japanese women

This study evaluates background serum levels of selected organochlorine compounds among Japanese women of reproductive age and investigates whether lifestyle factors, especially dietary factors, may be associated with these levels. A cross-sectional study was performed on 80 Japanese women, aged 26-43 years, who complained of infertility and were confirmed not to have endometriosis. The serum levels of total toxic equivalency (TEQ), 18 polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs), 4 coplanar polychlorinated biphenyls (cPCBs), 36 ortho-substituted polychlorinated biphenyls (PCBs), and 13 chlorinated pesticides or their metabolites were measured and data were collected on the women's age, residence, occupation, body mass index (BMI), smoking and alcohol habit and 6 dietary intakes (fish, meats, rice, vegetables, fruits and dairy products). The serum median level of total TEQ was 25.1 pg TEQ/g lipid, that of PCDDs/PCDFs/cPCBs was 11.5 pmol/g lipid, that of PCBs was 0.46 nmol/g lipid, and that of total pesticides was 1.32 nmol/g lipid. The serum levels of total TEQ, PCDDs/PCDFs/cPCBs, PCBs and pesticides were positively associated with age (P for trend=0.003, 0.01, 0.005 and 0.01, respectively) and frequent fish consumption (P for trend=0.002, 0.003, 0.0003 and 0.006, respectively). Other lifestyle factors were not associated with serum organochlorine levels. The present study suggests that Japanese women who consume fish frequently in their reproductive period tend to accumulate organochlorines in their bodies.

Dietary intake of PCDDs, PCDFs and dioxin-like PCBs, due to the consumption of various marine organisms from Korea

Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) residues were measured in 70 marine organisms (40 species) from Korean coastal waters. The PCDD/Fs residues in the organisms varied from 0.02 to 4.39 pg WHO-TEQ/g wet weight and the DL-PCBs residues varied from 0.008 to 6.0 pg WHO-TEQ/g wet weight. The levels in fish from Korean coastal waters were comparable to those found in other countries. Comparing organism groups, the highest PCDD/Fs and DL-PCBs residues were recorded in crustaceans, followed by fish, cephalopods, bivalves and gastropods. Although the congener distributions of PCDD/Fs and DL-PCBs in the organism groups were different, the dominant contributors to the total TEQ concentrations in all groups were 2,3,4,7,8-pentachlorinated dibenzofuran (PeCDF), 1,2,3,7,8-pentachlorinated dibenzo-p-dioxin (PeCDD) and PCB 126. The dietary intake of PCDD/Fs and DL-PCBs from the consumption of marine organisms in Korea was estimated to be 0.68 pg WHO-TEQ/kg bodyweight/day. The contribution of DL-PCBs to the total dietary intake from all organisms groups averaged 60%. The relative contribution of each organism group to the total dietary intake was, in descending order: fish, crustaceans, cephalopods, bivalves and gastropods. The current dietary intake was lower than those in countries with a similar dietary pattern to Korea, but higher than those in countries with smaller quantities of seafood consumption.

Degradation of polychlorinated biphenyls (PCBs) by Staphylococcus xylosus in liquid media and meat mixture

We investigated the growth of the meat starter Staphylococcus xylosus (10(4) cells mL(-1)) in liquid media containing 0.01 ppm of each polychlorinated biphenyls (PCBs 10, 28, 52, 138, 153, and 180) and its ability to degrade PCBs during 168 h of incubation in liquid media (10(4) cells mL(-1), 0.01 ppm of each PCB congener) and cured meat mixture (0.1% of meat starter, 1 microg g(-1) fat of each PCB congener). PCBs did not affect the growth of the starter microorganism in nutritive (brain heart infusion, BHI) or mineral salts medium (MSM) when compared to control (no PCB). S. xylosus degraded some of the PCB congeners tested. PCBs 138 and 153 were degraded both in BHI (78% and 68%, respectively; p<0.05) and in MSM (71% and 66%, respectively; p<0.05), with maximum degradation being observed within 24 h. Highly significant negative exponential relationships was observed between incubation time and concentrations of PCB 28 and 180 in BHI, as well as for PCBs 52 and 180 in MSM. In the cured meat mixture highly significant negative exponential relationship was observed between incubation time and the concentration of PCB 10. These results indicate that although S. xylosus reduced residues of various PCB congeners in liquid media, it was less effective in cured meat.

PCDDs, PCDFs and dioxin-like PCBs in food of animal origin (Slovakia)

The levels of 17 toxic polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and 12 non-ortho and mono-ortho polychlorinated biphenyls (PCBs) in 73 foodstuff samples of animal origin collected from shops and small farms in selected districts of Slovak Republic are presented in this paper. The concentrations expressed as WHO-TEQ in analysed samples ranged for PCDDs/PCDFs from 0.25 pg/g fat in pork to 75 pg/g fat in cod liver. The TEQ concentrations of non-ortho PCBs were between 0.007 and 181 pg/g fat and mono-ortho PCBs between 0.0083 and 66.5 pg/g fat. The mean concentrations in freshwater fish and imported species of marine fish were 0.089 pg TEQ/g fresh weight for PCDDs/PCDFs, 0.17 pg TEQ/g fresh weight for non-ortho PCBs and 0.034 pg TEQ/g fresh weight for mono-ortho PCBs. The mean total concentration of PCDDs/PCDFs and dioxin-like PCBs in samples of infant milk formula imported from EU countries was 0.98 pg TEQ/g fat.

Associations between dietary intake and breast milk dioxin levels in Tokyo, Japan

BACKGROUND

The presence of dioxins in breast milk has gained much attention recently. However, in Japan the relationship between the consumption of different foods and the human breast milk dioxin concentrations is still unclear.

METHODS

Breast milk was taken from 240 mothers residing in Tokyo, Japan to measure and analyze the concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and coplanar poly-chlorinated biphenyls contained in the fat. Individual milk samples were obtained from the mothers 30 days after delivery in 1999 and 2000. The data of the mothers' diets before pregnancy were collected by means of food frequency and amount estimation. Spearman correlation analysis and stepwise multiple linear regression were used to analyze the data.

RESULTS

The concentrations of dioxins in breast milk were influenced mainly by the mother's age and history of breast-feeding. All the Spearman correlation coefficients were less than 0.20. Pork, roast ham, sausage, salt codfish and tempura had negative correlations with breast milk dioxins.

CONCLUSIONS

History of breast-feeding and the mother's age should be considered and emphasized in this kind of analysis. The cause effect relationship between dietary intake and breast milk dioxin levels were still uncertain.

Polychlorinated biphenyls and organochlorine pesticides in human adipose tissue and breast milk collected in Hong Kong

Contamination from persistent organic pollutants is a pervasive global problem that urgently demands global concern and action. In the present study, concentrations of organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs) were determined in 37 samples of female adipose tissue collected in Hong Kong hospitals. Among the pollutants analyzed, DDTs (2.79 ng/g fat), HCHs (0.72 ng/g fat), and PCBs (0.19 ng/g fat) were prominent compounds in most of the adipose tissue. p,p'-DDE and hexachlorinated biphenyls were found in all samples, whereas heptachlor epoxide and dieldrin were found only in some samples. An estimation of toxic equivalency concentration (TEQ) due to dioxin-like coplanar PCBs was also performed. The estimated TEQ(PCBs) was 2.01 pg/g fat. This study also compared our previous results obtained from the milk samples of the same donors. Significant correlations are obtained for DDTs and HCHs between milk and adipose tissue. Detailed review of available information concerning OC pesticides and PCBs in different ecological compartments indicated that bioconcentration and biomagnification of these contaminants are common phenomena of the Pearl River Delta region, which has undergone rapid socioeconomic change in the past 20 years. It is suggested to establish a regional organization in order to coordinate the monitoring of persistent organic pollutants in the region.

Uptake of polychlorodibenzo-p-dioxins, polychlorodibenzofurans and coplanar polychlorobiphenyls in chickens

Twelve chickens raised according to commercial standards were fed a diet containing about 30 ng total toxic equivalent (TEQ)/kg for 10 weeks. Persistent pollutants were introduced into the poultry feed via recycled oil to mimic contamination conditions closely resembling those occurring during the Belgian crisis five years ago. Absorption of congeners with the same chlorination degree did not seem to depend on the substitution, demonstrating that unlike for cows, no preferential absorption for 2,3,7,8-substituted compounds could be remarked for chickens. As already observed, absorption decreased with increasing number of chlorines and was not linearly dependent on the octanol/water partition coefficient. On the other hand, no real differences were observed in the absorption of coplanar polychlorinated biphenyls (c-PCBs) with regard to degree of chlorination. When monitored during the course of experiment, concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and c-PCBs in excreta reached an apparent steady state after 5 weeks. Only 2,3,7,8-substituted dioxins or furans were found in tissues and eggs. All organs showed the same congener profile and similar lipid-normalized concentration, except for the liver. Bioconcentration factors were evaluated, highlighting that the liver preferentially retained highly chlorinated congeners. No depletion of dioxin and PCB concentration was observed after 8 and 14 weeks of control diet, but high inter-individual variation occurs.

Evaluation of serum dioxin congeners among residents near continuously burning municipal solid waste incinerators in Korea

The objective of this study was to evaluate the congeners of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in Korean serum samples as biological markers. Serum samples from 103 participants were analyzed. Participants consisted of 28 workers in municipal solid waste incinerators (MSWIs), and 21 men and 54 women who had lived for at least 3 years prior to 2002 in areas within 300 m of incinerators in large Korean cities. Serum samples were analyzed for 17 PCDD/PCDFs congeners by high resolution gas chromatography-high resolution mass spectrometry. Geometric mean (GM) PCDD/PCDF levels in the serum samples were 3.14, 8.04, 6.12 and 6.60 pg TEQ/g lipid for workers, male residents, female residents and the sum of male and female residents, respectively. The GM PCDD/PCDF level in the serum of workers was not significantly different from the values for residents near MSWIs. In the 75 participants who resided near MSWIs, the congeners that most contributed to the total TEQ were 1,2,3,6,7,8-hexachlorodibenzofuran (1,6-HxCDF), 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF), 1,2,3,4,6,7,8-heptachlorodibenzofuran (1,4,6-HpCDF), 1,2,3,7,8,9-hexachlorodibenzofuran (1,9-HxCDF), 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin (1,4-HxCDD), 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (1,6-HxCDD). In the workers, the congeners that made the greatest contribution were 1,6-HxCDD, 4-PeCDF, 1,2,3,4,6,7,8-heptachlorodibenzop-dioxin (HpCDD), and 1,6-HxCDF. In conclusion, the serum TEQ levels for PCDD/PCDFs in the incinerator workers and residents near the MSWIs in Korea were lower than those reported for other countries. Comparison of the PCDD/PCDF levels of workers at MSWIs and nearby residents revealed no significant enhancement of PCDD/PCDF exposure in workers. PCDD/PCDF intake from animal origin was assumed to be lower than that of Europeans. Further studies of Korean foods are needed to clarify the exposure route for PCDD/PCDFs in the Korean population.

Daily intake of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/PCDFs) in foodstuffs consumed in Tarragona, Spain: a review of recent studies (2001-2003) on human PCDD/PCDF exposure through the diet

Concentrations of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) were measured in foodstuffs randomly acquired in various locations of Tarragona County (Catalonia, Spain) in September 2002. A total of 36 composite samples, belonging to various food groups (vegetables, fruits, meat and meat products, fish and seafood, cereals, pulses, milk, dairy products, eggs, and oils and fats) were analyzed by high-resolution gas chromatography/high-resolution mass spectrometry. The dietary intake of PCDD/Fs was subsequently determined. For calculations, recent data on consumption of the selected food items were used. Total dietary intake of PCDD/Fs for the general population of Tarragona County was estimated to be 59.6 pg I-TEQ/day (63.8 pg WHO-TEQ/day). Fish and seafood (33.7%), oils and fats (15.3%), cereals (14.4%), and dairy products (13.7%) were the most important contributors to this intake. This PCDD/F intake is notably lower than the intake estimated in 1998 for the same geographical area, 210.1 pg I-TEQ/day. The current PCDD/F dietary intake is below the tolerable intake range of 1-4 pg TEQ/kg body weight/day established by the WHO in 1998. Finally, the current intake is compared with the dietary intakes of PCDD/Fs recently (2001-2003) reported for a number of regions and countries.

Background exposure to PCDDs/PCDFs/PCBs and its potential health effects: a review of epidemiologic studies

Here we review epidemiologic studies dealing with the dietary intake and the body burden of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzo-furans (PCDFs)/ polychlorinated biphenyls (PCBs) in the general population, and potential adverse health effects of these substances, especially on the risk of diabetes mellitus and endometriosis, and on thyroid function and the neurodevelopment of infants. The mean or median intake of dioxin-related compounds among the general populations of various countries is lower than the maximum tolerable daily intake (TDI) set by the WHO in 1998 (4pg TEQ/kg/day). However, there have been few reports on the distribution of intake and the proportion of subjects whose exposure levels exceed the maximum TDL. At present, it remains unclear whether background exposure to dioxin-related compounds is associated with increased risk of diabetes (because of lack of longitudinal studies), endometriosis (because of lack of studies with sufficient statistical power), or altered thyroid function (because of inconsistent results on humans). Consistent results have been reported for the association between exposure to background levels of PCBs/dioxins, especially trans-placental PCBs, and defective neurodevelopment of infants in the U.S. and Europe. Thus, efforts should be made to further decrease the body burden among women of reproductive age by reducing the release of PCDDs/PCDFs/PCBs into the environment.

Dietary intakes of polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls in Spain

Congener-specific analyses of seventeen 2,3,7,8-substituted PCDD/Fs, three non-ortho and 8 mono-ortho dioxin-like polychlorinated biphenyls (PCBs) were performed on 258 Spanish foodstuff samples, mainly of animal origin, for 2000--03. Daily dietary intakes of PCDD/Fs and PCBs, expressed as toxic equivalents (WHO-TEQs), were estimated by combining food consumption data from the Spanish National Institute Statistics survey and concentration levels measured in individual samples, using upper bound determination values (not detectable = limit of detection). The calculated dietary intake of PCDD/Fs for a person weighing 70 kg was 1.35+/-0.11pg WHO-TEQs kg(-1) bw day(-1), and 3.22+/-0.75 pg WHO-TEQs kg(-1) bw day(-1) if dioxin-like PCBs (non- and mono-ortho PCBs) were included, showing the importance of their inclusion in monitoring studies. Both values were within the range of tolerable daily intake (TDI) proposed by the WHO (1-4pg WHO-TEQs kg(-1) bw day(-1)). The current levels are lower than earlier intakes estimates conducted in Spain. Meat and meat products accounted for more than 35% of the intake, followed by milk and milk products (29%), vegetables oils (19%), fish and seafood (11%) and eggs (4%). Dioxin-like PCBs are an important component in the total WHO-TEQs in foodstuffs. This is particularly true for the fish food group, where the total WHO-TEQs is dominated by dioxin-like PCBs (up to 80% of WHO-TEQs in some cases).

Market basket study on dietary intake of PCDD/Fs, PCBs, and PBDEs in Finland

We have measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDD/F), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDE) in 10 market baskets consisting of almost 4000 individual food samples representing 228 different food items, and also in the total diet basket. Lower bound concentrations of PCDD/Fs ranged between 0.0057 and 5.6 pg/g fresh weight in the market baskets and the corresponding values for PCBs from 39 to 25,000 pg/g. The fish basket contributed most to the concentrations of dioxins and PCBs, and also to concentrations of PBDEs in which the lower bound range was from 0.82 to 850 pg/g. We also assessed the average daily intakes of these substances by the Finnish adult population. The average daily intake of sum of PCDD/Fs and PCBs as WHO toxic equivalents was assessed to be 115 pg, which was 1.5 pg WHO-TEq/kg body weight using an average mean weight of 76 kg for the general population in Finland. The contribution of fish to the intake of PCDD/Fs was between 94% and 72%, depending on whether lower or upper bound concentrations were used. With respect to PCBs, the contribution of fish was 80%. The calculated intake of PBDEs of 44 ng/day was comparable to intake assessments from other countries. Fish also contributed most to the PBDE intake, but there was some other source of PBDEs that distinguishes the exposure to PBDEs from exposure to PCDD/Fs and PCBs. This additional source seemed to be found in the market basket that included beverages, spices, and sweets.

Infant exposure to polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls (PCDD/Fs, PCBs)--correlation between prenatal and postnatal exposure

Polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are recognized environmental endocrine disruptors, which are environmentally persistent and may bio-accumulate in human bodies. Pregnant and nursing women may pass these pollutants to their babies both trans-placentally and lactationally. We measured and examined correlations of the levels of PCDD/Fs and PCBs in perinatal venous serum, placenta, umbilical-cord serum (representing prenatal exposure), and breast milk (postnatal exposure). Subjects included pregnant women without clinical complication between the ages of 25 and 35, who delivered their babies during 2000.12.01 and 2001.11.30 in central Taiwan. A total of 20 participants were randomly selected from those provided the four biological specimens for analysis of 17 PCDD/Fs, and 12 dioxin-like PCBs and six indicator PCBs using high-resolution gas chromatography/high-resolution mass spectrometry. Higher PCDD/F levels were found in placenta (10.3 TEq-pg/g lipid) and venous serum (9.1 TEq-pg/g lipid) compared to those in breast milk (7.6 TEq-pg/g lipid). Pearson and Spearman correlation analyses showed well association of PCDD/F and PCB levels between different specimens. The total dioxin/PCB level in milk, venous and cord serum can be well predicted by that in placenta through regression functions. This first study of multi-specimen correlation further established rather consistent ratios of these chemical concentrations in various specimens relative to those in venous serum.

Levels of PCDDs, PCDFs and PCBs in Belgian and international fast food samples

Congener-specific analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) were performed on twenty-eight non-pooled fast food samples collected in Belgium, Switzerland, Czech Republic, United States of America and Australia. PCDD/F and PCB concentrations for the four investigated types of meals were very low. PCDD/F values ranged from non-detected to 1.40 pg WHO-TEQ/g fat and from 0.79 to 2.08 pg WHO-TEQ/g fat for lower and upper bound, respectively. Major contributors to the PCDD/F TEQ were 1,2,3,4,7,8-HxCDD, 1,2,3,6,7,8-HxCDD, 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF. The relative contribution of PCBs to the total TEQ was 68%. For adults, an average estimated intake was 6.7 pg WHO-TEQ/kg bw/month, including consumption of all types of analyzed meals, representing 9.5% of the PTMI. For child, a value of 14.5 pg WHO-TEQ/kg bw/month was obtained, representing 20.6% of the PTMI.

Survey of commercial pasteurised cows' milk in Wallonia (Belgium) for the occurrence of polychlorinated dibenzo-p-dioxins, dibenzofurans and coplanar polychlorinated biphenyls

Congener-specific analyses of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs) and 4 non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 35 samples of commercial long-life pasteurised cows' milk issued from eight different brands available in Walloon supermarkets (Belgium). The observed congener profile was characteristic of milk samples issued from industrialised countries with good inter and intra-brand reproducibility's. The PCDDs to PCDFs ratio was equal to 1.8 in concentration. The toxic equivalent (TEQ based on WHO-TEF) value for PCDD/Fs in all analysed milks was 1.09+/-0.30 pg TEQ/g fat (range 0.86-1.59), which is below the recommended EU non-commercialisation threshold value of 3 pg TEQ PCDD/Fs/g of milk fat. The mean TEQ value including cPCBs was 2.23+/-0.55 pg TEQ/g fat. These PCBs actually contributed for 49+/-8.6% of the total TEQ. Among PCDD/Fs and cPCBs, tetrachloro dibenzo-p-dioxin (TCDD), pentachloro dibenzo-p-dioxin (PeCDD), pentachloro dibenzofurans (PeCDFs) and 3,3',4,4',5-pentachloro biphenyl (PCB-126) were the most important contributors to the TEQ. Estimated daily intake (EDI) due to consumption of such milks was 0.34 pg TEQ/kg of body weight/day for PCDD/Fs and 0.69 pg TEQ/kg of body weight/day when cPCBs were included.